NEW ORLEANS—The oil spill in the Gulf of Mexico has already spewed plumes over ecologically sensitive reefs, part of a stalled marine sanctuary proposal that would have restrict drilling in a large swath of the northern part of the vital waterway.
Marine scientists fear that two powerful Gulf currents will carry the oil to other reefs. The eastward flowing loop current could spread it about 450 miles to the Florida Keys, while the
The depth of the gushing leaks and the use of more than 560,000 gallons of chemicals to disperse the oil, including unprecedented injections deep in the sea, have helped keep the crude beneath the sea surface. Marine scientists say diffusing and sinking the oil helps protect the surface species and the Gulf Coast shoreline but increases the chance of harming deep-sea reefs, which are seen as bellwethers for sea health.
"At first we had a lot of concern about surface animals like turtles, whales and dolphins," said Paul Montagna, a marine biologist at Texas A&M University Corpus Christi who studies Gulf reefs. "Now we're concerned about everything."
On Sunday, researchers said computer models show oil has already entered the loop current that could carry the toxic goo toward the Keys, the third-longest barrier reef in the world.
The oil is now over the western edge of a roughly 61-mile expanse of 300-to-500-foot-deep reef south of Louisiana known as the Pinnacles, about 25 miles north of where the Deepwater Horizon exploded April 20, killing 11 people and starting the spill that grows by the hour.
The Pinnacles is one of nine coral banks and hard-bottom areas stretching from Texas to Florida that the National Oceanic and Atmospheric Administration tried in 2008 to get designated a marine sanctuary called Islands in the Stream.
This sanctuary would have restricted fishing and oil drilling around the identified reef "islands." But the plan was put on hold after vehement objections from Republican lawmakers, fishermen and the oil industry.
Scientists have found undersea plumes of oil at the spill as much as 10 miles long, which are an unprecedented danger to the deep sea environment, said Samantha Joye, a professor of marine sciences at the University of Georgia.
These plumes are being eaten by microbes thousands of feet deep, which removes oxygen from the water.
"Deepwater coral are abundant on the sea floor in this part of the Gulf, and they need oxygen," said Joye, who was involved in the plume discovery. "Without it, they can't survive."
Experts say the well's depth and Friday's decision by the U.S. Environmental Protection Agency to allow BP to shoot massive amounts of dispersing chemicals deep underwater may help protect vital marshes and wetlands on the Gulf Coast. But the tradeoff may result in significant effects on more sea life.
Oil mixed with the chemical agent can disperse into the water more easily, rather than it staying on the surface, where it could bypass deeper banks like Pinnacles, said Edward Van Vleet, a chemical oceanography professor at the University of South Florida.
The downside is that it causes oil to sink, coating corals and other reef organisms and smothering them, he said.
When the dispersed oil is broken into smaller globules, he said they are more easily eaten by smaller reef organisms and can kill them or cause tumors or something else harmful.
Federal officials who oversee marine sanctuaries and fisheries say it's too early to tell how reefs and other important habitats may be damaged, said Dr. Jane Lubchenco, NOAA's undersecretary of commerce for oceans.
NOAA, which manages marine sanctuaries, is also responsible for estimating financial costs of the spill on the sea environment and fisheries. The Pinnacles is a significant habitat for sea life vital to commercial fisheries such as red snapper, crab and shrimp.